Metal Ion Effects on Fullerene/Porphyrin Cocrystallization

Abstract

This investigation presents a systematic examination of the late transition metal octaethylporphyrins MII(OEP) with M = Co, Ni, Cu, and Zn as cocrystallization agents for C60. In each case, the fullerene was dissolved in benzene and then layered over an equimolar dichloromethane solution of the porphyrin. A striking new columnar structural type for these systems is found for CoII(OEP) and ZnII(OEP) with stoichiometric ratios 6:5 for porphyrin/fullerene. In these cocrystals, one fullerene is surrounded by two porphyrins, one is adjacent to only one porphyrin, while one makes no contact with a porphyrin; yet, all three fullerenes are ordered at 90 K. A more typical, also new, 1:1 structure with CuII(OEP) and C60 shows back-to-back porphyrins with all eight ethyl groups embracing the fullerene. In these three structures only dichloromethane is found as the solvate. The NiII(OEP) structure is related to the known structure of NiII(OEP)·C60·2C6H6 but has incorporated ca. 5% dichloromethane. In these NiII(OEP)/C60 cocrystals, four of the ethyl groups embrace the fullerene, while the other four are displaced to the opposite side of the porphyrin plane where they do not make contact with a fullerene. The porphyrin core conformations of the different metal derivatives also differ, and their possible impact on cocrystal formation is discussed.

Solvent and Solvate Effects on the Cocrystallization of C60with CoII(OEP) or ZnII(OEP) (OEP = Octaethylporphyrin)

“…Although cocrystallization of fullerenes with Ni II (OEP) has been used to determine the structures of endohedral fullerenes − and fullerenes with holes in their surface , by many different research groups, there are several factors that are involved in crystal growth, including the role of the specific metal ion in the porphyrin and the solvents and other variables in the crystallization process. Recently, we demonstrated that cocrystallization of C 60 with M II (OEP) with M = Co, Ni, Cu, and Zn showed significant differences among the four different metalloporphyrins . For example, cocrystallization of Co II (OEP) and Zn II (OEP) with C 60 from a benzene/dichloromethane mixture produced the remarkable crystals 6Co II (OEP)­·5C 60 ·5CH 2 Cl 2 and 6Zn II (OEP)­·5C 60 ·5CH 2 Cl 2 , henceforth designated as 6:5Co and 6:5Zn respectively, that contained one C 60 molecule sandwiched between two porphyrin molecules in a clam shell arrangement, one C 60 molecule adjacent to only one porphyrin molecule, and one C 60 molecule that made no contact with any porphyrin as seen in Figure .…”

Rotation of fullerene molecules in the crystal lattice of fullerene/porphyrin: C60 and Sc3N@C80

“…Recently, the effect of the metal ion in the porphyrin and the role of the solvent in the crystallization of C 60 /MOEP (M=Co, Ni, Cu, and Zn) was thoroughly investigated. 18,19 However, the temperature driven fullerene molecule dynamics in the crystal lattice of co-crystals with MOEP are still unclear for this type of fullerene. The structure of the nitride clusterfullerene Sc 3 N@C 80 was reported more than two decades ago.…”

Functional Carbazole‐Fullerene Complexes: A New Perspective of Carbazoles Acting as Nano‐Octopus to Capture Globular Fullerenes

“…3,3',5,5'-tetra(9H-carbazol-9-yl)-1,1'-biphenyl (TCBP) was synthesized via a typical Suzuki coupling reaction from 9,9'-(5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,3-phenylene)bis(9Hcarbazole) and 9,9'-(5-bromo-1,3-phenylene)bis(9H-carbazole) according to the reported literature. [23b] The 1 H NMR, 13 C NMR and MS (MALDI-TOF) spectra of DCB and TCBP are shown in Figure S11-S16. All solvents were HPLC grade.…”

“…Fullerene‐porphyrin association has also been proven useful as a structure‐defined tool to produce strong π ‐ π interactions and covalent conjugations between the ring juncture of fullerene and electropositive center of porphyrin [12] . Additionally, metal coordination enables metalloporphyrins prevalent cocrystallization with almost any fullerene [13] . Meanwhile, better orbital overlapping between hetero‐fragments has been achieved upon the introduction of metal ions, which could enhance ambipolar mobility [14] .…”

“…[12] Additionally, metal coordination enables metalloporphyrins prevalent cocrystallization with almost any fullerene. [13] Meanwhile, better orbital overlapping between hetero-fragments has been achieved upon the introduction of metal ions, which could enhance ambipolar mobility. [14] Besides, some macrocycles depart significantly from planarity to be domed or warped for stronger concave-convex π-π interactions with fullerenes.…”